33 



plant food more available ; they improve the general physical con- 

 ditions of a compact, clayish soil by rendering it more mellow and 

 permeable. As a direct addition of plant food they are only in 

 exceptional cases of real importance ; they are in the majority of 

 cases worthless upon a calcareous soil. 



Marls and clayish marls, free from any perceptible amount of 

 potash and phosphoric acid, act in the main similarly to the pre- 

 viously mentioned lime refuse. Earthy composts of various de- 

 scriptions, if applied in large quantities, frequently act very 

 beneficially on exposed portions of the upper part of grass roots 

 by protecting them against an undesirable exposure to light and 

 atmosphere, thereby favoring the formation of new and more 

 numerous shoots. They benefit the inherent stock of plant food 

 only as much as they contain one or more of them in an available 

 condition, which is usually an unknown quantity. 



Other substances, quite frequently of a mere local interest, might 

 be added to the previous list, if space permitted. 



Most of these previously stated manurial substances, it will be 

 noticed, are only temporary remedies, if any. They assist more 

 or less in economizing existing local resources of plant food. 

 They may, however, if used intelligently, quite frequently serve 

 as valuable helpmates in a more rational and more comprehensive 

 economical system of manuring grass lands capable of a remuner- 

 ative improvement. As an economical source of phosphoric acid, 

 aside from ground bone, which furnishes phosphoric acid and 

 nitrogen, in many instances finely ground mineral phosphate from 

 Florida, South Carolina, "West Indies and other localities deserve 

 recommendation for grass lands as a top-dressing, on account of 

 low cost. Kainite and muriate of potash are to-day our most effi- 

 cient and cheapest sources of potash for forage crops. 



Wood ashes are a valuable fertilizer for grass lands, if applied 

 in sufficient quantities ; our average unleached Canada wood ash 

 contains from 5 to 6 per cent of potassium oxide, 1.5 to 2.5 per 

 cent of phosphoric acid and 30 to 35 per cent of calcium oxide 

 (lime), besides small quantities of every other essential mineral 

 constituent required for a successful growth of plants. The ab- 

 sence of nitrogen is somewhat compensated for by the presence of 

 a liberal amount of lime, which favors a rapid decomposition of 

 the vegetable matter contained in the Soil. The nitrogen of the 

 vegetable refuse matter becomes thereby in a high degree avail- 

 able. The good effect of wood ashes is for this reason more strik- 

 ing upon grass lands, rich in vegetable refuse matter, than upon 

 dry lands, which as a rule contain less of the latter. 



The good services of barn-yard manure for the production of 



